@book{MSM_1926__14__1_0,
     author = {De Donder, Th\'eophile},
     title = {Th\'eorie des champs gravifiques},
     series = {M\'emorial des sciences math\'ematiques},
     publisher = {Gauthier-Villars},
     number = {14},
     year = {1926},
     language = {fr},
     url = {http://www.numdam.org/item/MSM_1926__14__1_0/}
}